The cook-tops mentioned herein are preferably though not exclusively intended for domestic use. They comprise a plurality of localized cooking sections for heating the contents of kitchen utensils. The heating means generally comprise elements for heating by the Joule effect, by radiation or by induction. During use the heating element must be turned on, the power consumption must be adjusted, in some cases several times, and finally the heating element must be turned off.
When the utensil is lifted briefly, the user does not necessarily intend to stop the operation of the heating element. This may have different consequences for example,
there is a useless electric power dissipation, and
the temperature of the heating element, which then operates without load, is difficult to control and the element may produce radiation which may hinder or even harm the user by dazzling or scalding.
Therefore, it is desirable that the operation of the heating element can be controlled during said operations. Obviously, this should not have any consequences for the operation of the other heating elements.
U.S. Pat. No. 4,476,946 describes a cook-top which can be used as a weighing platform and which controls the electric power consumed by a plurality of heating elements arranged in the platform. According to the patent, one or several heating elements can be arranged separately in a system of strain gauges which bend under the influence of a load placed on the heating element. These strain gauges are electrically arranged as a Wheatstone bridge and thus enable the weight of the load placed on the heating element to be determined. This measure can be used for controlling, for example, the evaporation rate of the load when this is, for example, a pan containing a liquid, by controlling the electric power consumed by the heating element.
However, such a cook-top poses cleaning problems. The heating elements and the cooking sections are movable relative to the platform, which requires a certain clearance which inevitably gives rise to leakage. Therefore, this cook-top does not meet current demand, which attaches great importance to the cleaning facilities and the ease of cleaning the cook-top.
An object of the present invention is therefore to identify a means to combine easy cleaning and the detection of the presence or absence of a load on an arbitrary heating element in order to identify this element to allow its operating conditions to be influenced.